1. Field of the Invention
The subject invention relates to a suspension assembly for an automotive vehicle, and more particularly to a torsion bar suspension system and an adjustment lever for adjusting the torsion in the torsion bar.
2. Description of the Prior Art
A torsion bar suspension system of the type having a suspension height adjusting mechanism is well known in the art and is widely used in an automotive industry today. Such a torsion bar suspension system includes a lower control arm having a typical A-frame construction that mounts the torsion bar at its legs and mounts upper and lower ball joints at its opposite end. A torsion bar adjustment arm, i.e. a lever, is mounted on the torsion bar and has an arm that extends radially from the torsion bar to engage an adjustment bolt carried on the vehicle frame to raise or lower the position of the adjustment arm. Adjusting the position of the adjustment arm has the effect of applying more or less torque on the torsion bar, which in turn raises or lowers the front of the vehicle.
Over time, the torsion bar has a tendency to relax or weaken, causing the front end of the vehicle to sag. When the vehicle is serviced, a technician can raise the front end a certain amount by raising the adjustment arm via the adjustment bolt. However, in many cases, the torsion bar has relaxed beyond the range of adjustment of the arm, such that the vehicle can no longer be brought back into the original specification for alignments. Accordingly, the torsion bar must be replaced at considerable cost.
U.S. Pat. No. 2,713,484 to Pierce, U.S. Pat. No. 3,432,158 to Goodwin, U.S. Pat. No. 4,243,247 to Kataoka, U.S. Pat. No. 4,863,148 to Hufnagel, U.S. Pat. No. 5,186,216 to Bollier, U.S. Pat. No. 6,364,297 to Weber, and U.S. Pat. No. 6,454,284 to Worman, Jr. show a variety of mechanisms and suspension systems for adjusting the torsion in a torsion bar to adjust the height of the front end of the vehicle. Many of these prior art designs are complex, bulky in structure and require considerable space under the vehicle body to allow the operator to adjust the systems. Furthermore, at least some current designs require replacement of the relaxed torsion bar to restore a ride height due to insufficient adjustment travel in a production torsion bar adjustment lever.
A need exists for a suspension mechanism or system for adjusting the torsion in a torsion bar without replacing the torsion bar.